1. Field of the Invention
The present invention relates to processing signals. More particularly, the present invention relates to a system and method for processing audio signals.
2. Description of the Related Art
A traditional stereo loudspeaker system setup typically includes a left speaker and a right speaker both positioned on the same horizontal plane with each speaker being equal distance from the listener, i.e., the traditional stereo loudspeaker system is of symmetric configuration. There are three major techniques for symmetrically configured stereo speakers to expand their corresponding sound fields. These techniques include a delaying tactics approach, a polar exploration approach, and a split EQ approach.
In the delaying tactics approach, a small delay is introduced into one side of a stereo signal. Very short delays, of the order of a few milliseconds, are not generally perceived as echoes, but as changing the apparent position of the source signal within the stereo field. Once the delays get beyond 5 ms, the effect is less obvious. However, as the delays extend beyond 15 ms, the ear of the listener will be able to increasingly distinguish the delayed signal as a separate sound, which is not desirable.
The polar exploration approach is to take a little of the left channel, reverse the polarity and mix it into the right channel, and vice versa.
In the split EQ approach, complementary EQ settings on the left and right channels will emphasize the differences between them; thus, creating more sense of width. This produces a very subtle width enhancement provided that the EQ settings are matched accurately.
All the above approaches are not applicable for non-symmetric stereo speaker systems (e.g., in which speakers are positioned very close to each other and/or positioned on different horizontal planes). Further, the above approaches often generate very subtle enhancements even for symmetric stereo speakers systems.
Accordingly, goals of this invention include addressing the above problems by providing an effective and simple stereo widening system and its real-time implementation.